1. Field
Example embodiments relate to semiconductor devices and methods of manufacturing semiconductor devices, and more particularly, to non-volatile memory devices having a cross point cell array and methods of manufacturing the same.
2. Description of the Related Art
A flash memory device has an advantage of low manufacturing cost in that the same silicon-based manufacturing processes for DRAM devices may be applied to the flash memory manufacturing processes. However, the flash memory device has disadvantages of a relatively lower integration degree and operation speed together with relatively higher power consumption for storing data in comparison with the DRAM devices.
Thus, various next generation nonvolatile memory devices such as a PRAM (phase changeable RAM) device, an MRAM (magnetic RAM) device and a RRAM (resistive RAM) device have been suggested so as to overcome the above disadvantages of the flash memory devices. Most of the next generation nonvolatile memory devices have a lower power consumption, so a small access time and a large amount of the disadvantages of the nonvolatile memory devices can be solved or alleviated by the next generation nonvolatile memory device.
Particularly, a three-dimensional cross point array structure has been intensively studied in recent times for increasing the integration degree of the nonvolatile memory devices. In the cross point array structure, a plurality of upper electrodes and a plurality of lower electrodes cross each other and a plurality of memory cells is arranged at every cross point of the upper and lower electrodes. Thus, random access can be possible to each of the memory cells of the cross point array structure, and the data programming to each memory cell and the data reading from each memory cell can be individually conducted with high operating efficiency.
A unit cell is provided at a cross point of the upper and lower electrodes and a plurality of the unit cells is vertically stacked, thereby forming the three-dimensional cross point array structure of the next generation nonvolatile memory devices. The three-dimensional cross point array structure can significantly increase the integration degree of the next generation nonvolatile memory device.